Low-temperature synthesis of high-entropy amorphous metal oxides (HEOs) for enhanced oxygen evolution performance.

The rational design of multiple metal ions into high-entropy oxide electrode material via a single-step hydrothermal process is applicable to the evolution of oxygen molecules (O2) through simple water electrolysis. Their cost-effectiveness, high performance, and durable nature are the key factors of non-precious high-entropy multiple metal-based electrocatalysts, which can be used as replaceable catalysts instead of precious ones. This article reports a low-temperature synthesis of the cauliflower-type morphology of high-entropy amorphous metal oxides, and their electrochemical performances towards the oxygen evolution reaction (OER) are investigated. The multiple metal ion (Mn2+, Fe3+, Co2+, Ni2+, Cu2+) oxide electrode material shows an acceptable oxygen evolution reaction (OER) with an overpotential of 290 mV at a current density of 10 mA cm-2 and a lower Tafel slope value of 85 mV dec-1, respectively. Moreover, the 20 h durability test with negligible change in overpotential shows the efficacy of the modified electrode material in harsh alkaline media. The observed electrochemical results towards the OER correspond to the amorphous nature of the active material that displayed a cauliflower-type morphology, having a large specific surface area (240 m2 g-1) and providing higher electrochemical active sites as well. Consequently, post-stability characterization studies (such as PXRD, FESEM, TEM, and XPS) provide more information for understanding the post-structural and morphological results of the high-entropy amorphous metal oxide.

Veno-venous ECLS rescue for a heart transplant recipient with COVID-19, a case report.

The potential for increased rates of morbidity of SARS-CoV-2 within immunocompromised populations has been of concern since the pandemic's onset. Transplant providers and patients can face particularly challenging situations, in the current settings as data continues to emerge for the prevention and treatment of the immunocompromised subpopulation. This case report details a patient 9-months post orthotopic heart transplant that developed SARS-CoV-2 infection despite two prior doses of the Pfizer-BioNtech COVID-19 vaccine, and had successful rescue from refractory hypoxemia with veno-venous extracorporeal membrane oxygenation (VV ECLS).

Positive donor blood cultures are not associated with worse heart transplant survival.

BACKGROUND: Recent evidence has demonstrated that transplantation of hearts with blood culture positive donors (BCPDs) to pediatric recipients is safe and effective. Few studies have analyzed the effect of BCPD on adult heart transplant recipients. METHODS: The United Network for Organ Sharing (UNOS) database was retrospectively reviewed from September, 1987 to March, 2021. Exclusion criteria included pediatric donors/recipients, donor ejection fraction <10% or >85%, inactive listed recipients, donors missing blood cultures, and recipients missing follow-up time. Outcomes were compared with fully adjusted logistic models. To account for discrepancies in BCPD and non-BCPD covariates, an inverse proportionally weighted model with regression adjustment (IPWRA) was used. RESULTS: A total of 60 592 donors were non-BCPD, while 4009 were BCPD. 7% of hearts not transplanted were BCPD, while 6% of hearts transplanted were BCPD (p = .001). These rates have been nearly constant since 2005. There were no differences in short term survival between the two groups in the adjusted or IPWRA models (p = .103 and .277, respectively). Additionally, the BCPD group had longer ischemic time (3.24 vs. 3.06 h, p < .001), older donor age (32.73 vs. 31.65 years, p < .001), and older recipient age (52.76 vs. 52.09 years, p = .001). The IPWRA revealed an average additional 3.4 years of overall survival and 2.25 years of graft function for BCPD versus non-BCPD recipients, although these results failed to reach statistical significance (p = .387 and .527, respectively). CONCLUSIONS: Given the need for more donor hearts, donors with positive blood cultures should be considered. Great care in evaluating such patients is advised to eliminate donors with untreated infections, while carefully selected donors can be considered and used.

Pre-emptive intraoperative administration of PCC4 in cardiac surgery patients at high risk of bleeding: A pilot study.

BACKGROUND: Four-factor prothrombin complex (PCC4), a concentrate of factors II, VII, IX, and X and proteins C and S, has been used selectively for reversal of oral anticoagulation before surgery. There is data to support PCC4 as opposed to supplemental fresh frozen plasma (FFP) to manage postoperative bleeding following cardiac surgery. The preemptive, intraoperative use of PCC4 in cardiothoracic surgery has not been studied though it may prevent postoperative bleeding, the need for blood transfusion and the risk of transfusion-related acute lung injury, volume overload, and right ventricular (RV) heart failure. The purpose of this study is to evaluate the intraoperative administration of PCC4 to decrease bleeding and lower the rate of blood transfusion. METHODS: A single institution retrospective chart review was conducted from May 2020 to November 2021 of patients who received PCC4 intraoperatively during cardiothoracic surgery of high-risk variety. Patients were evaluated for the type of surgery, demographics, baseline anticoagulation, PCC4 dose, type and quantity of blood transfusion within 72 hours (h) postoperatively, chest tube output, the incidence of RV failure, hypersensitivity reactions, acute kidney injury (AKI), thrombosis, acute lung injury, and mortality within 45 days of the operative dose of PCC4. RESULTS: Thirty-five patients received PCC4 at a mean dose of 2920 units (U). Sixty-five percent of cases were left ventricular assist devices (LVADs) or heart transplants. The protocol is to use PCC4 30 units (U)/kg immediately after the completion of protamine administration. Inclusion criteria are cardiothoracic surgery with increased risk of postoperative right heart failure commonly secondary to blood product transfusion, or cardiothoracic surgery associated with increased risk of bleeding, including heart transplant, LVAD implant, aortic dissection, and redo sternotomy (e.g., coronary artery bypass). Total chest tube output was recorded as a mean of 757 ml for 24 h after surgery (32 ml/h). Overall median event rates of FFP and red blood cell (RBC) transfusions were 0 (interquartile range [IQR]: 0-3 U) and 4 (IQR: 2-5 U). Overall, 43% and 89% of cases received FFP and RBC, respectively. There was one occurrence of RV failure, one occurrence of AKI requiring renal replacement therapy, one occurrence of venoarterial extracorporeal membrane oxygenation, one occurrence of venous thromboembolism related to a central venous access line, and one death unrelated to surgery or PCC4 that was attributed to advanced heart failure not amenable to advanced therapies. CONCLUSION: Overall patients received a low rate of blood transfusion, had minimal chest tube output, and there was a small incidence of right heart failure. Patients did not have an increased risk of adverse effects such as AKI or venous thromboembolism. A randomized controlled clinical trial comparing the observed dose and timing of PCC4 versus routine postoperative bleeding management with blood product transfusion is recommended.

Ischemic time and patient outcomes after the 2018 UNOS donor heart allocation system change.

BACKGROUND: The allocation system for heart donors in the United States changed on October 18, 2018. The typical distance from donor hospitals to recipient hospitals has increased as has the ischemic time. We investigated patient outcomes with the new allocation system and the differential effects of ischemic time under both the old and new allocation schemas. METHODS: The United Network for Organ Sharing Registry (UNOS) was queried for data regarding heart transplants occurring from October 1, 1987 to March 1, 2021. In total, 62,301 adult heart transplants were examined. Survival outcomes at 30 days and 1 year and ischemic times were compared via adjusted logistic and Cox models (overall survival and time until post-transplant rejection). RESULTS: Mean ischemic time was slightly increased in the new system (3.43 h vs. 3.03 h, p < .001). Survival differences between old versus new systems were not observed in adjusted models (p = .818). However, there was evidence to suggest longer ischemic times are more detrimental to long-term survival under the new system (hazard ratio [HR] = 1.15 per hour increase; p = .001) versus the old system (HR = 1.08 per hour increase; p < .001), although this relationship did not reach statistical significance (p = .150). CONCLUSIONS: Although travel distances have significantly increased under the new allocation system, survival outcomes remain largely unchanged. Ischemic time is an influential factor in recipient survival that should be limited during organ transport. Further studies on the impact of travel distances and ischemic time under the new allocation system are needed.

Successful recovery with venovenous ECMO for ARDS after LVAD HeartMate 3 implantation: A case report.

Acute respiratory distress syndrome (ARDS) following left ventricular assist device (LVAD) implantation is a rare complication. Venovenous (VV) extracorporeal membrane oxygenation (ECMO) is used as a treatment for severe ARDS and pneumonia. We report the successful use of VV ECMO for ARDS Klebsiella pneumonia following urgent LVAD HeartMate 3 implantation.

Functional status of heart transplant recipients predicts survival.

INTRODUCTION: Recipient functional status prior to transplantation can significantly impact post-transplant survival. METHODS: The United Network for Organ Sharing database was queried for adult heart transplants including data on functional capacity and from February 1, 2005 to March 1, 2021; there were 32 875 cases included. The four functional categories studied were based on adult daily activities of living and were separated into total assistance required, some assistance required, no assistance required, and near death. Survival outcomes were compared for recipient's pretransplant level of functional status versus those with near death status. These were compared using adjusted logistic regression (odds of death at 30 days and 1 year) and conditional Cox models (overall survival and time until post-transplant rejection). All models were adjusted for donor age, sex, ethnicity, ischemic time, as well as recipient age, sex, ethnicity, length of stay, UNOS region, ventricular assist device, creatinine, days on the waiting list, and status at transplant. RESULTS: There were 12 953 recipients classified as "near death" or "severely disabled"; 7711 "required total assistance in daily living", 7,328 "needed some", and 4883 "needed none". In adjusted models, the probabilities of death for the lowest functioning groups within 30 days and 1 year were 5% and 10%, respectively. Those "requiring total assistance" had analogous probabilities of 3% (OR = 0.58; p < 0.001) and 9% (OR = 0.81; p < 0.001). Those "requiring some assistance" had probabilities of 3% (OR = 0.56; p < 0.001) and 9% (OR = 0.74; p < 0.001). Lastly, those "requiring no assistance" had probabilities of death of 2% (OR = 0.35; p < 0.001) and 7% (OR = 0.63; p < 0.001). CONCLUSION: Recipient functional status assessed pre-transplant and recorded in the UNOS database is a strong predictor of post-transplant survival.

Isolated left ventricular assist device implantation produces variable changes to patient body mass index.

BACKGROUND: Body mass index (BMI) is an important consideration for transplant-eligible left ventricular assist device (LVAD) recipients. LVAD therapy's impact on BMI is unclear. We evaluated BMI changes in patients who underwent LVAD implantation. The association between these patients' BMI and the transplant was studied. METHODS: This was a retrospective cohort study of patients who underwent LVAD implantation between January 1, 2012 and December 31, 2018 at our institution. Patients were stratified by preoperative BMI (kg/m2 ) into four groups: <30, 30-34.9, 34.9-39.9, and ≥40. BMI data were collected at 12 and 6 months prior to implantation, time of implantation, and 3- and 6- months postimplantation. RESULTS: A total of 107 patients underwent LVAD implantation at our institution. Data were available for 80 patients. Baseline characteristics included a mean age of 56.0 years, 69% male, and a mean implant BMI of 29.9 ± 6.8 kg/m2 . The mean BMI (kg/m2 ) for each of the BMI (kg/m2 ) groups <30, 30-34.9, 35-39.9, and ≥40 (n = 60, 25, 12, and 10, respectively) was 25.1, 32.5, 36.8, and 43.8, respectively. There was no consistent pattern with weight change across differing implant BMIs. No patient with a BMI of <30 gained sufficient weight to impact transplant candidacy. Twenty-three percent of patients with a BMI of 30-34.9 kg/m2 , 60% of patients with a BMI of 35-39.9 kg/m2 , and 87.5% of patients with a BMI of ≥40 kg/m2 had a 6-month BMI potentially affecting transplant. CONCLUSIONS: Associated weight changes during LVAD support may significantly impact transplant candidacy. Higher BMI groups may benefit from multimodal and multidisciplinary targeted weight-loss interventions.

Impella 5.0: An intermediate strategy for bridging a patient from infected durable LVAD to cardiac transplant.

Cardiac transplant remains the gold-standard treatment for end-stage heart failure more than 50 years after the procedure was first pioneered. The number of transplant operations performed annually has been limited by the global imbalance of donor organs to recipients. This imbalance helped fuel the development of left ventricular assist devices (LVADs) first as a bridge to cardiac transplant and subsequently as destination therapy. Driveline infection is one of several problems that continue to plague LVADs through several generations of improvement. We present a patient with an infected LVAD driveline exit site that progressed to mediastinitis, pericardial and pump infection. The device was explanted, and the patient supported with an axillary Impella 5.0 as a bridge until the time of transplant. An Impella 5.0 (or 5.5) can be used as an intermediate tool to be able to explant an infected LVAD, with mediastinitis, allowing the patient to clear the infection, and prepare the patient for transplant free of infection. METHODS: The patient consented to the study and case report. The patient signed an informed consent and permission for publication.

Transcarotid Approach to Placement of an Impella 5.0.

Microaxial left ventricular assist devices (mLVADs) have traditionally been placed through a transfemoral or transaxillary arterial approach. Transfemoral access is restrictive, significantly limiting postoperative patient ambulation. Transaxillary placement is preferred but not feasible in a subset of patients due to small arterial diameter or tight angulation of the thoracic outlet. Transcarotid delivery has been utilized for other cardiovascular device deployment with good success; however, this approach has not been described for mLVAD support. We present a case series of transcarotid placement of mLVADs in cases where a transaxillary and transfemoral approach was not feasible. From May 2017 to April 2019, six patients in cardiogenic shock required mLVAD support achieved via a transcarotid approach. Technical success was achieved in all patients. One patient was directly weaned from mLVAD support and two patients died on mLVAD support. Escalation to venoarterial extracorporeal membrane oxygenation (VA-ECMO) was required for three patients, two of whom subsequently died. There were no bleeding or valvular complications related to device placement, and no obvious or known neurologic complications related to mLVAD support. Transcarotid placement of mLVADs expands the utility of these devices as an alternative to traditional support strategies or prohibitive arterial anatomy; however, further study is needed to determine its efficacy.

Seasonal trends in donor heart availability: an analysis of the UNOS database.

Despite the widespread belief that donor organ availability varies around holidays and seasons, there is little empirical data supporting this long-held belief. Variations in donor heart availability may be of interest to patients and clinicians. The UNOS/OPTN registry was queried for all heart donations from October 1987 through March 2017. Daily heart donation rates were modeled nationally using Poisson regression including splines for year and day of the year. Seasonality was assessed using a likelihood ratio test for the spine terms for day of the year. The holiday effect was assessed using conditional logistic regression. Seasonal plots suggest a significant, although modest, increase in organ availability during the summer months, except for region 1. The regions with the highest amplitude were region 7 (peak: June 21, amplitude: 16.63%) and region 6 (peak: July 5, amplitude: 11.29%). There was no significant difference in the odds of heart donation when comparing holidays vs. non-holidays using national data (odds ratio [95% CI]: 1.01 [0.98, 1.03], P = 0.560) or any regional subsets. There was no observable correlation between donor heart availability and holidays. However, a significant seasonality effect was observed with higher donation rates occurring during warmer months.

Sustained Use of the Impella 5.0 Heart Pump Enables Bridge to Clinical Decisions in 34 Patients.

We studied whether sustained hemodynamic support (>7 d) with the Impella 5.0 heart pump can be used as a bridge to clinical decisions in patients who present with cardiogenic shock, and whether such support can improve their outcomes. We retrospectively reviewed cases of patients who had Impella 5.0 support at our hospital from August 2017 through May 2019. Thirty-four patients (23 with cardiogenic shock and 11 with severely decompensated heart failure) underwent sustained support for a mean duration of 11.7 ± 9.3 days (range, ≤48 d). Of 29 patients (85.3%) who survived to next therapy, 15 were weaned from the Impella, 8 underwent durable left ventricular assist device placement, 4 were escalated to venoarterial extracorporeal membrane oxygenation support, and 2 underwent heart transplantation. The 30-day survival rate was 76.5% (26 of 34 patients). Only 2 patients had a major adverse event: one each had an ischemic stroke and flail mitral leaflet. None of the devices malfunctioned. Sustained hemodynamic support with the Impella 5.0 not only improved outcomes in patients who presented with cardiogenic shock, but also provided time for multidisciplinary evaluation of potential cardiac recovery, or the need for durable left ventricular assist device implantation or heart transplantation. Our study shows the value of using the Impella 5.0 as a bridge to clinical decisions.

Bariatric surgery in patients with advanced heart failure: A proposed multi-disciplinary pathway for surgical care in medically complex patients.

BACKGROUND: The objective of this study was to develop a multi-disciplinary care pathway to minimize perioperative complications in patients with advanced heart failure undergoing bariatric surgery. Patients with severe obesity and heart failure carry increased perioperative surgical risk compared to patients with no heart failure due to the severity of their cardiac disease state and associated comorbidities. Our bariatric program routinely excluded patients with advanced heart failure from undergoing bariatric surgery due to the high reported perioperative risk. However, knowing the potential beneficial impact of bariatric surgery for advanced heart failure, our program hoped that the thoughtful development of a perioperative pathway before inclusion of patients with advanced heart failure in the bariatric surgery program could minimize the morbidity of these high-risk patients in comparison to prior publications in the literature. METHODS: Two multi-disciplinary care pathways were developed, including advanced heart failure, anticoagulation specialists, and transplant cardiologists, to optimize bariatric care for severely obese patients with advanced heart failure with or without mechanical circulatory support and implementation was evaluated for short-term 30-day complications and 6 month cardiac and weight-loss outcomes. RESULTS: Two multi-disciplinary care pathways were developed and implemented on 5 patients with heart failure with reduced ejection fraction (pathway 1) and 3 patients requiring mechanical circulatory support (pathway 2). There were no in-hospital complications or mortality following either pathway, and there was only 1 emergency room visit and 1 re-admission. The average length of stay for patients with heart failure with reduced ejection fraction without mechanical circulatory support was 2.4 days and for heart failure with reduced ejection fraction with mechanical circulatory support was 4.3 days. Three patients met body mass index criteria for transplant listing at 6 months. Ejection fraction increased an average of 9% at 6 months postoperatively for patients with heart failure with reduced ejection fraction not requiring mechanical circulatory support. CONCLUSION: With multi-disciplinary care pathway development designed to maximize safety by intensely supporting preoperative cardiac optimization and medication titration postoperatively, bariatric surgery can be performed in patients with advanced heart failure with or without mechanical circulatory support, allowing patients the opportunity for weight loss as a bridge to transplant or potentially meaningful cardiac recovery.

A Dual-Lumen Percutaneous Cannula for Managing Refractory Right Ventricular Failure.

A right ventricular assist device (RVAD) using a dual-lumen percutaneous cannula inserted through the right internal jugular vein (IJV) might improve weaning in patients with refractory right ventricular (RV) failure. However, the reported experience with this cannula is limited. We reviewed the records of all patients receiving RVAD support with this new dual-lumen cannula at our institution between April 2017 and February 2019. We recorded data on weaning, mortality, and device-specific complications. We compared outcomes among three subgroups based on the indications for RVAD support (postcardiotomy, cardiogenic shock, and primary respiratory failure) and against similar results in the literature. Mean (standard deviation [SD]) age of the 40 patients (29 men) was 53 (15.5) years. Indications for implantation were postcardiotomy support in 18 patients, cardiogenic shock in 12, and respiratory failure in 10. In all, 17 (94%) patients in the postcardiotomy group were weaned from RVAD support, five (42%) in the cardiogenic shock group, and seven (70%) in the respiratory failure group, overall higher than those reported in the literature (49% to 59%) for surgically placed RVADs. Whereas published in-hospital mortality rates range from 42% to 50% for surgically placed RVADs and from 41% to 50% for RVADs with percutaneous cannulas implanted through the right IJV, mortality was 11%, 58%, and 40% in our subgroups, respectively. There were no major device-related complications. This percutaneous dual-lumen cannula appears to be safe and effective for managing refractory RV failure, with improved weaning and mortality profile, and with limited device-specific adverse events.

Association of preoperative duration of inotropy on prevalence of right ventricular failure following LVAD implantation.

AIMS: 20% to 40% of left ventricular assist device (LVAD) device implantations are complicated by right ventricular (RV) failure that results in significant morbidity and mortality. We hypothesized that the duration on milrinone infusion is an independent risk factor for RV failure following LVAD implantation. METHODS AND RESULTS: Retrospective demographic, clinical and hemodynamic data were collected on all adults with ACC/AHA stage D heart failure on intravenous milrinone who underwent LVAD implantation between 2012 and 2019. Patients (n = 104) were divided into two groups, those on milrinone <30 days (STM, n = 55) vs. ≥30 (LTM, n = 49). The primary endpoint was the prevalence of RV failure (need for inotropic support for more than 14 days or RV assist device) within 30 days post-LVAD implantation. There were no significant differences between STM and LTM patients with respect to demographic, echocardiographic, right heart catheterization data, or baseline medications. The mean age of patients was 55.6 ± 12 years (70% male patients). Mean duration on milrinone was 13.7 vs. 81.0 days in STM and LTM, respectively. Forty-five (43.3%) patients developed RV failure. LTM had higher prevalence of RV failure with odds ratio (OR) = 5.04 (95% CI 2.18-11.68, P = 0.0002). After adjusting for age, gender, and co-morbidity count, the OR was 6.33 (95% CI 2.51-15.93), P < 0.0001. CONCLUSIONS: In this retrospective study of ACC/AHA stage D HF patients, longer duration of milrinone infusion was associated with higher prevalence of RV failure after LVAD implantation.

Minimally Invasive Mechanical Circulatory Support Through the Perioperative Pulmonary Thromboendarterectomy Period: A Case Report.

A 64-year-old man being evaluated for pulmonary thromboendarterectomy (PTE) preoperatively experienced pulseless electrical activity secondary to right ventricular failure while undergoing bronchoscopy. After return of spontaneous circulation, a percutaneous right ventricular assist device (RVAD) was placed through the right internal jugular vein. He continued on right ventricular support with demonstration of right ventricular recovery over the following 8 days, and subsequently underwent PTE for treatment of his primary condition. He recovered and was weaned from his RVAD support uneventfully. The need for RVAD support has traditionally been a contraindication for PTE; however, circulatory assist devices have been used as a salvage procedure for right-heart failure after PTE. This case highlights the potential for percutaneous mechanical circulatory support in treating severe perioperative right ventricular dysfunction, and to facilitate successful recovery in patients undergoing PTE.

Burden of arrhythmia and electrophysiologic procedures in alcoholic cardiomyopathy hospitalizations.

BACKGROUND: Limited national US data are available regarding the prevalence of and trends in different arrhythmias and the use of electrophysiological procedures in patients with alcoholic cardiomyopathy. METHODS: This was a cross-sectional study that used the Nationwide Inpatient Sample database (2007-2014). Hospitalizations of adults with alcoholic CMP were identified with the ICD-9 code (425.5). CAD and other causes of cardiomyopathy were excluded. Chi-square test, t-test, mixed-effect logistic regression and quantile regression were used. RESULTS: Among 75,430 hospitalizations, 48% had arrhythmias. Individuals with a co-diagnosis of arrhythmia tended to be older (56.9 vs 53.2-year-old) and male (89.5% vs 81.9%). The most prevalent arrhythmias were atrial fibrillation/flutter (31.5%), followed by ventricular tachycardia (7.9%). The prevalence of arrhythmias increased from 44% to 50% (2007-2014) (p < 0.001) and this increase was mainly secondary to the increasing prevalence AFib/AFL. Excluding cardiac arrest, arrhythmias were not associated with increased in-hospital mortality. The median length of stay and total charges for arrhythmia vs no-arrhythmia hospitalizations were 5 vs 4 days (p < 0.001) and $31,127 vs $24,199 respectively (p < 0.001). EP procedures were performed in 5.6% of all hospitalizations and it increased from 5.2% to 6% (2007-2014) (p = 0.2). The most common procedures were cardioversion (2.7%), ICD placement (2.2%) and PPM placement (1.1%). CONCLUSION: Arrhythmias were reported in 48% of hospitalizations. There was an increasing burden of arrhythmias secondary to increasing atrial fibrillation. Excluding cardiac arrest, arrhythmias were not associated with increased in-hospital mortality but were associated with longer hospital stays and higher total charges.